Side wire gap wrench for spark plugs



June 30, 1931. H. RABEZZANA 1,812,495

SIDE WIRE GA? WRENCH FOR SPARK PLUGS Filed Nov. 25, 1929 QUF 'I W 4Patented June 30, 1931 UNHTED STATES HECTOR RABEZZAN A, OF FLINT,MICHIGAN, ASSIGNOR TO A C SPARK PLUG COMPANY,

PATENT OFFICE OF FLINT, MICHIGAN, A COMPANY OF MICHIGAN SIDE WIRE GAP\VRENCH FOR SPARK PLUGS Application filed November 25, 1929. Serial N 0.409,607.

This invention has for its object to provide a small and low cost handtool or gap wrench for spark plugs, intended primarily for distributionamong motor car owners and garage mechanics to enable them by its use to-quickly and easily adjust to proper size the spark gap or space betweenthe spark plug electrodes.

A preferred embodiment of the invention is shown in the accompanyingdrawings, wherein Figure 1 is a perspective view of the wrench.

Figure 2 is a side elevation showing the wrench applied to a spark plug,part of the plug being shown in section.

Figure 3 is a transverse sectional view taken on line 3-3 of Figure 2.

Figures 4 and 5 are transverse section views, similar to Figure 3,showing the parts in different positions of adjustment.

The wrench as shown in the drawings, and which for convenience andeconomy of manufacture may be a forging, comprises a lever 6 to fit inthe operators hand, having at one end a lateral semi-cylindricalprojection or boss 7. This boss is adapted for insertion within the boreat the lower end of the spark plug shell 8, with its peripheralparti-circular surface fitted or' seated against the insidecorresponding surface of the bore, thereby providing a bearing for thelever which permits the lever to be swung about the longitudinal axis ofthe spark plug. In order to clear the central electrode 9 projectingthrough the core 10, the boss or head 7 is provided with a substantiallyU-shaped notch 11, leaving a pair of legs or wedge like members 12 and13 spaced on opposite sides of the center or axis of the peripheralsurface, and receiving therebetween the central electrode.

Figure 4 shows in a somewhat exaggerated manner the side wire orelectrode 14 which projects laterally from the shell beside the centralelectrode 9 spaced quite a distance from the central electrode, so thatthere is a very large gap across which the spark must jump. To correctthis condition the lever 6 with its head inserted in the bore may beswung in a counter-clockwise direction whereby the leg 12 will enter andwedge itself between the free end of the electrode 14 and the side wallof the shell, and the inner cam-like surface of this leg will upon continued movement of the lever cause the electrode 14 to be bent inward ortoward the central electrode to shorten the gap therebetween. The dottedlines in Figure 4 illustrate the position of the parts when the gap isreduced to proper size.

If, on the other hand, the gap should be too small, as is illustrated inFigure 5 where the electrodes are in actual contact, then the swingingmovement of the lever is reversed and the tip of the leg 13 contactswith the electrode 14 and wedges it away from the central wire until theparts assume the position indicated by the dotted lines in Figure 5.

From the above description it will be apparent that an efficient butsimple and inexpensively manufactured gapping tool is proelectrodes of aspark plug or the like, including a hand lever, a boss on the hand leverinsertable into the central opening thru the plug shell and engageablewith the wall of the shell to provide a fulcrum for the lever,

whereby the lever may be swung about the axis of the plug, and a partengageable with one of the electrodes to bend the same when the lever isswung.

2. A tool for adjusting the spark gap in a spark plug wherein the shellelectrode projects laterally from the shell and along side the centralcore electrode. including a substantially U-shaped part insertable intothe.

shell bore and slidable on the interior surface of the shell about theplug axis, with the open space of the U receiving the central electrodeand its legs projecting therebeyond for engagement with the shellelectrode by one or .70 vided by which the sparking gap in a plug,

. 1. In a tool for adjusting the gap between the other thereof uponmovement of the part about said axis to bend said shell electrode towardor from the central electrode.

3. A tool for adjusting the gap between spark plug electrodes, includinga rockable lever having a curved bearing surface for sliding engagementon a corresponding-surface of a spark plug shell, and a pair ofelectrodeengaging parts spaced from each other other electrode.

and on opposite sides of the axis of said bearing surface, whereby oneor the other o'fsaid parts engage the electrode upon lever movement tomove the electrode to or from the 4 A tool for adjusting the gap betweenspark plug electrodes, including a part having'a curved bearing surfacemovable over a corresponding surface of the spark plug I gaging surfaceeccentric to said bearing surshell, and an abutment spaced from the axisof said curved surface for engagement with one of the electrodes to varythe position of the same upon movement of said part.

5. A tool for adjusting the gap between spark plug electrodes, includinga hand lever having a lateral boss provided with a particircular bearingsurface and an electrode enface.

6. A tool for adjusting the gap of a spark plug, including a partinsertable in-the bore of the spark plug shell and having a peripheralsurface adapted to ride on the inner sur- 7 face of the shell, and a camsurface to engage an electrode, and means to rotate said part to bendthe electrode by the engagement'therewith of the cam surface.

In testimony whereof I afix my signature. HECTOR'RABEZZANA.

